This invention relates generally to instrumentation displays for automotive vehicles; more specifically it relates to a shift prompter/driver information display for a highway truck.
The development of microelectronic circuits that are suitable for automobile usage has resulted in the creation of information displays for presenting useful information to the driver of the vehicle.
Typical data that is presented by an on-board microcomputer-based display comprises; engine speed, vehicle speed, fuel consumption, truck mileage, elapsed trip time. Instantaneous and average values of these parameters can also be displayed. Examples of such displays are found in the following U.S. Pat. Nos.: 4,447,860; 4,463,427; D 275,944; D 276,039; D 277,176; 4,635,034; 4,663,718; and 4,706,083.
Another form of display that is useful in certain motor vehicles is one that is used to indicate when a transmission is being operated in gear that for one reason or another is not the optimal gear for the particular operating conditions. The intent of displaying this type of information is to encourage the driver of the vehicle to shift to a more optimal gear. Typically these gear change signaling systems monitor fuel consumption and are intended to inform the driver that better fuel economy can be obtained in a different gear and therefore they serve to encourage the driver to shift to a gear that will result in more economical fuel consumption.
Examples of change gear signaling systems are found in the following U.S. Pat. Nos.: 4,494,404; 4,539,868; 4,544,909; 4,570,226; 4,683,455; and 4,701,852.
The present invention relates to a new and improved integrated powertrain display in which information about the operation of the vehicle powertrain is presented to the driver of the vehicle in a display that is organized and arranged in a new and unique format. The display is operable to three different modes of operation which are respectively referred to as the cruise mode, the prompt mode, and the shift mode.
The cruise mode of operation is characterized by engagement of the clutch and the transmission in gear. In the cruise mode of operation the display presents information concerning the powertrain operation and selected by the driver from the following functions: fuel economy; engine speed; vehicle speed; trip time; trip distance; and engine operating time. A particular generalized function (principal category of information) that is selected for display by the driver of the vehicle is often characterized by different modes (or sub-categories) and therefore the display has: the ability to further refine the selection in terms of a particular selectable mode. In the illustrated display these selectable modes are as follows: total; goal; average; instantaneous; and remaining. Obviously not all of these modes are applicable to all of the functions. For example, the remaining mode would have no meaning with respect to engine speed. However, in the case of fuel economy the instantaneous, the goal and the average modes would all be applicable.
The prompt mode of operation is initiated during the cruising mode whenever the microcomputer control determines that the transmission should be operated in a different gear from the particular gear in which it is presently operating. Accordingly, the display contains an upshift indicator and downshift indicator that are activated whenever upshifting or downshifting is called for. The intent is that the driver will observe the signal for either an upshift or a downshift and then make the appropriate gear change.
The display operates to the shift mode whenever the control determines that the driver is in the process of shifting the transmission. Specifically the shift mode occurs when either the clutch pedal is depressed and/or the transmission lever is placed in neutral. The display advises the driver of the identity of the target gear that is indicated and it also activates a two color indicator lamp that is used to aid the shifting. The two color indicator lamp serves the purpose of indicating, first by one color (red), the initiation of a non-proportionality indicative of a shifting operation being in progress; then once the engine speed has been brought to a speed that is within a predetermined range of synchronous speed for the target gear, the light switches to the second color (green) indicating that the shift can be completed. Once the transmission has been placed into gear and the clutch reengaged, the shift mode of operation ceases and the display reverts to the cruising mode of operation.
Associated with a numerical digital read-out of the display is an analogue display that is in the form of a series of bars that can be selectively illuminated. The particular number of segments that are illuminated produces a corresponding illuminated length of this analogue display, and hence by controlling the number of segments that are illuminated, the length of the display is selectively illuminated. The length is related to different functions in the cruise and shift modes of operation of the display. In the cruise mode of operation, the analogue display provides a useful analogue indication in conjunction with a digital miles per gallon display and in the shift mode of operation the analogue display can provide an indication of the approach of engine speed to synchronous gear meshing speed.
The foregoing, along with additional features, advantages, and benefits of the invention, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings disclose a presently preferred embodiment of the invention according to the best mode contemplated at the present time in carrying out the invention.